In a number of control systems, for example transportation vehicle operation control systems, there is a need for amplifier apparatus which is failsafe in its operation. One of the main considerations in the design of amplifier apparatus for use in such a system is that the amplifier apparatus gain be controlled within safe limits in the event of a failure in the amplifier apparatus.
According to the here described apparatus, an improved failsafe inverting amplifier is disclosed which is widely useful and relatively economical when compared with failsafe inverting amplifiers of the prior art.